Bike Reviews

A newer player in the category, Quarq released the CinQo Saturn in 2008, among the first cranksets to compete with SRM. It uses 10 strain gauges—two on each of the spider's five arms—to measure both torsional and lateral flex. Taken together, the company says, these two metrics result in accurate power readings (+/-2 percent).

Quarq, recently acquired by SRAM, offers its CinQo Saturn as either a complete unit with crankarms from one of several companies or as an upgrade to most cranks with removable spiders. There are CinQos for standard and compact road rings, and an off-road version. Quarq does not offer its own head unit, but the Saturn is compatible with any ANT+ wireless head unit. We used a Garmin Edge 500 and analyzed data in Training Peaks.

We tested the Saturn with a SRAM S900 crank and found both shifting and stiffness to be good. In addition to calibrating the unit before each ride, it's also advisable to recalibrate when the weather changes midride for the best accuracy, as even small weather fluctuations can affect measurements. A crank-based system does not transfer easily between bikes, but it's a good choice as long as you plan to race and train on only one bike. Within the category, the Saturn gives you two distinct advantages over SRM: price and serviceability. Our test model costs about $1,000 less than a comparable model from SRM, and a user-changeable battery powers the unit. In one year of heavy use, we replaced the battery twice, a simple process that takes less than a minute (plus a trip to RadioShack).

The boxy Quarq isn't slick-looking like an SRM crank, but it's just as accurate, and with the cost savings it's a good choice.—Andrew J. Bernstein